Britney Spears has rejected a $10 million offer to judge the next season of “The X Factor,” TheWrap has learned.

So the question is: How much is Fox going to have to pony up? Try $20 million.

Reports this week that the pop star was considering a $10 million offer to judge next fall’s seasons of “The X Factor” are out of date, according to a knowledgeable individual in Spears’ camp.

The singer rejected that offer three weeks ago and is instead thinking about an offer to become a resident performer at a Las Vegas hotel in the fall, a la Celine Dion.

So here comes a game of chicken. Fox desperately needs a big name to announce on the judge’s panel of Simon Cowell’s show, now that NBC’s hit show “The Voice” will be competing with them in the fall.

Spears’ camp wants $20 million. (EvenI think that’s ridiculous and Fox won’t pay that.)

But the reality is it’s becoming an arms race for singing talent being paid to sit behind tables and… talk.

NBC has put its money where its mouth is, paying Christina Aguilera upward of $10 million to come back and judge the new season of “The Voice.” They’ve given handsome paychecks, if not as much, to the other judges as well.

What Fox has shelled out for the “X Factor” judges pales in comparison. Paula Abdul was paid $2.5 million for the last season, according to another knowledgeable insider, and she was announced at the 11th hour.

She was also fired, as were judge Nicole Scherzinger and host Steve Jones.

“X Factor” is already recording its audition phase, but won’t need the judges until the end of May.

Fox wouldn't comment. Spears' camp wouldn't comment. Simon Cowell's camp wouldn't comment.

But what the network wants is a big piece of news to present to advertisers at their upfront sales presentations on May 14.